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A series of dihydro- and tetrahydro-tetraazaacene diimides containing 6 or 7 laterally fused six-membered rings were synthesized. Halochromic and redox-switchable vis-NIR optical characteristics were exhibited. Quinonoid tautomers of dihydrotetraazaacene derivatives were obtained and characterized, which exhibited adequate stability and existed in equilibrium with the more commonly observed benzenoid tautomer.